1. Field of the Invention
The invention relates to a drive support device and a drive support method.
2. Description of Related Art
In recent years, some of vehicles, such as automobiles; are equipped with a drive support device that supports driver's driving operation. For example, Japanese Patent Application Publication No. 2010-191518 (JP 2010-191518 A) describes a drive support device that executes drive support so that a vehicle is able to appropriately cross an intersection on the basis of a travelling state of the vehicle and a state of a traffic signal. The drive support device determines whether a host vehicle is able to cross a signalized intersection ahead of the host vehicle on a green light when the host vehicle is guided to accelerate (depress an accelerator pedal). When it is determined that the host vehicle is able to cross the signalized intersection ahead of the host vehicle on a green light when the host vehicle is guided to accelerate, the drive support device executes acceleration guiding function through an accelerator indicator to prompt a driver to accelerate in a section before the signalized intersection. When it is determined that the host vehicle is not able to cross the signalized intersection ahead of the host vehicle on a green light even when the host vehicle is guided to accelerate, the drive support device executes red light running prevention function through an alarm to prompt the driver to decelerate or stop in the section before the signalized intersection.
In addition, Japanese Patent Application Publication No. 2009-289007 (JP 2009-289007 A) describes a vehicle travelling speed indication method that compares an actual travelling speed of a vehicle with a recommended travelling speed or corrected recommended travelling speed that serves as a reference value fixedly indicated on a display screen and that indicates the actual travelling speed of the vehicle as a relative value with respect to the reference value.
The device described in JP 2010-191518 A or the method described in JP 2009-289007 A is able to notify the driver of a travelling condition in which the vehicle is able to cross a traffic signal by indicating a guide to prompt acceleration or indicating a recommended travelling speed. However, in the device described in JP 2010-191518 A or the method described in JP 2009-289007 A, an indicated target travelling speed or accelerating instructions may be significantly different in condition from a present travelling state or a target acceleration or travelling speed, and it may be required to drive the vehicle under a strict condition in order to perform travelling that satisfies the condition. In this way, when there is a possibility that the driver is guided to drive the vehicle under a strict condition, the driver may feel psychological burden from indicated support information.